The invention relates to an electric trimmer having a housing whose longitudinal dimension is substantially greater than its transverse dimension, an electric driven motor which is accommodated in the housing, and a trimming cutter set which comprises a stationary trimming cutter and a cooperating trimming cutter which is reciprocatable by the motor. The cutters are each provided with a row of teeth and are together disposed near one end of the housing, in such a manner that the rows of teeth project from the housing; resilient means resiliently press the two trimming cutters against each other.
Electric trimmers may be distinguished between trimmers which are destined for professionals and trimmers which are destined to be used by amateurs at home. Trimmers of the first category should comply with stringent requirements as regards reliability and lifetime. This type of apparatus is therefore of very strong construction, the cutters of the trimming cutter set being very heavy and rugged and projecting completely or almost completely from the apparatus, so that they can be cleaned continually and easily. Trimmers of the last-mentioned category, however, are home appliances and must therefore be manufactured at the lowest possible cost price. When selecting the materials and the method of manufacturing the trimming cutter set, allowance is to be made for the fact that in most families a trimmer will be used with a comparatively low frequency so that even in the case of a relatively high wear, the lifetime of the trimmer will be appreciable. For this type of appliance the trimming cutters are therefore made of sheet steel, the material being hardened after the teeth have been formed and the cutters have been bent to shape, and being face-ground at the location of the rows of teeth and at a location opposite thereto. This type of trimming cutters is not mounted entirely outside the trimmer housing. For the most part they are mounted inside the housing and the stationary trimming cutter is connected to fixed parts thereof. Only a small part of the trimming cutters, near the rows of teeth, projects from the housing. It is evident that this presents certain problems with respect to the cleaning of the cutters and the surrounding part of the trimmer.
An electric trimmer of the present type is known from German Patent Application 2,241,284, which has been laid open for public inspection. To aid in cleaning, this known appliance is provided with a detachable section of the housing which can be removed without the use of tools and to which the trimming cutter set is secured. A plastic guide member is secured to the movable trimming cutter with the aid of screws, this guide member being provided with two cams which extend through the movable cutter into two guide slots of the stationary trimming cutter. In the detached condition of the detachable housing section, the stationary trimming cutter faces the open side and is rigidly connected to the housing section with the aid of two self-tapping screws. Thus, the stationary trimming cutter covers the movable trimming cutter. The last-mentioned cutter is pressed against the underside of the stationary trimming cutter with the aid of two conical, helically wound springs which are disposed between the plastic guide member and the housing section.
This known trimmer can be cleaned to a limited extent only. Hair clippings may readily collect between the two trimming cutters and also between the movable trimming cutter and the housing section. These normally inaccessible spaces become accessible only when the two self-tapping screws are removed, after which the various parts can be detached and cleaned completely. The two self-tapping screws are fitted in hollow protrusions which are integral with the housing sections. When the trimming cutter set is fitted for the first time, the self-tapping screws cut thread into the plastics projections. As is known, turning self-tapping screws several times into and out of a plastic does not promote a firm connection between the parts to be connected, because eventually the thread will be damaged beyond repair, so that the firm connection is impaired.